Etude cytologique de la prehypophyse du pigeon pendant la couvaison et la lactation

Résumé Les hypophyses de 22 Pigeons des deux sexes sacrifiés soit pendant la couvaison, soit pendant la période de soins aux jeunes, ou lactation, ont été comparées à celles de 43 Pigeons des deux sexes, adultes non lactants ou prépubères, normaux ou soumis à divers traitements (lumière permanente, métopirone, thyroxine). Elles ont toutes été examinées en microscopie optique et 13 d'entre elles ont été en outre étudiées au microscope électronique.Sur la base de leurs affinités tinctoriales et de leurs caractères histochimiques, 6 types cellulaires ont pu être identifiés (Tableau 2). Seuls trois d'entre eux, tous localisés dans le lobe céphalique de l'adénohypophyse, sont intensément modifiés pendant la couvaison et la lactation. D'une part, la cellule eta, érythrosinophile, et la cellule kappa, cyanophile mais PAS négative, sont fortement stimulées. D'autre part, la cellule delta, cyanophile et PAS positive, est déprimée.Les caractères ultrastructuraux de ces six types cellulaires sont décrits et plus particulièrement ceux des cellules sollicitées pendant la couvaison et la lactation.La confrontation de l'évolution respective de ces trois types cellulaires avec celle de la paroi du jabot montre que la cellule eta érythrosinophile élabore la prolactine. La signification fonctionnelle de la cellule kappa demeure hypothétique: elle élaborerait l'hormone mélanophorotrope, MSH. La valeur thyréotrope des cellules delta est démontrée par les modifications déclenchées à leur niveau par des injections de thyroxine; ces modifications sont identiques à celles observées pendant la lactation.

---

Summary The pituitaries of 22 pigeons of both sexes fixed either during incubation or lactation (care for the young) were compared with those of 43 adult pigeons that were either adult but non-lactating, or prepuberal; these were either normal or variously treated (permanent illumination, administration of metopirone or thyroxin). All were studied with the light microscope and 13 among them were also examined with the electron microscope. On the basis of their staining properties and histochemical characteristics, six cellular types were identified. Only three among these, all located in the cephalic lobe of the adenohypophysis are intensively modified during incubation and lactation On the one hand, the eosinophilic eta cell and the cyanophilic but PAS-negative kappa cell are strongly stimulated. On the other hand, the cyanophilic and PAS-positive delta cell is depressed. The ultrastructural characteristics of these six cell types are described, in particular of those involved in incubation and lactation. Comparison of the development of these three cell types and of the crop shows that the eta cell furnishes prolactine. The functional significance of the kappa cell remains hypothetical; it may produce the melanophorotropic hormone (MSH). The thyrotropic nature of the delta cell is demonstrated by its modification in response to thyroxin administration; these changes are identical with those observed during lactation.

---

---

Ce travail est dédié à M. le Prof. Bargmann à l'occasion de son 60^e anniversaire et en témoignage de notre respectueuse admiration.

---

Avec la collaboration technique de Mmes Denise Lescanne, et Renée Picart et de M. Claude Pennarun pour les photos.     

Influence de la cure chirurgicale de la varicocele sur la qualite du sperme

The aim of this study was to assess the efficacy of surgical varicocèle repair in terms of sperm quality. We have performed a retrospective study including 62 patients. All of them underwent clinical evaluation. A sperm analysis has been done before and after surgical repair. Before sugery, the spermogram was normal in only 11.3%. Oligospermia was found in 62.1 % of cases while 6.5% of patients had azoospermia. Abnormalities like microcephalia were encountered in 36.8% of cases. All patients underwent surgical varicocele repair. They were followed up every three months up to 18 months. A significant improvement of sperm count was found in 18 cases, with a pregnancy rate of 6.45%. Alterations of sperm quality was most severe in older patients. We think that as far as natural history of varicocele is not well established, the duration of its evolution is well correlated with the severity of sperm alterations. So, need for precocious diagnosis in order to lessen the risk of infertility.     

Contribution à la connaissance de la faune marine de la côte belge

Summary The difference of phototropism and phototaxis of both molluscs influenced their fixation.The orientation of both molluscs is towards the incoming light-direction, less pronounced when the light-intensity to the center of the tile is decreasing. The density of the populations of oysters is increasing towards the center of the tiles by decreasing light-intensity, the density of the Crepidula-population decreasing towards the center of the collector.The competition of both organisms in relation to space, is, under the opposed influence of the light, less than described in the literature.Theoretically it is possible to separate Crepidula and oyster-fixation, using this property.Statistical analysis corroborated our observations.     

Irradiations europeennes dans la vegetation de la Kroumirie

Sans résuméCommunication de la Station Internationale de Géobotanique Méditerranéenne et Alpine, No. 112.Reçue par la rédaction le 22.I.1952.     

Recherches sur la respiration de la cellule vivante

Sans résumé     

Sur la vascularisation de la lame terminale humaine

Résumé La lame terminale de l'homme, comme celle de nombreuses classes de vertébrés, est occupée par un système vasculaire remarquable.A partir de sources artérielles constituées dans les cas les plus typiques de quatre pédicules, un réseau capillaire superficiel tapisse la face pie-mérienne ou antérieure de la lame terminale; le sang de ce réseau est drainé dans un réseau profond formé de capillaires sinusoides groupés en anses ou en boucles dans la partie haute de l'organe, tandis que sa partie basse est occupée par un vaste plexus. Le sang du réseau profond gagne ensuite des veines communes à d'autres régions hypothalamiques qui se déversent dans le système des veines cérébrales antérieures.L'aspect des vaisseaux de la lame terminale et leur organisation particulière permet de penser qu'ils interviennent dans la fonction encore inconnue de l'organe vasculaire de la lame terminale.

---

On the vascularisation of the lamina terminalis in the human

Summary The human supra-optic crest like that of numerous classes of vertebrates, has a highly differentiated vascular system.From the arterial supply usually consisting of four pedicles, a superficial capillary network covers the pia-mater or anterior side of the supra-optic crest. The blood in this superficial network is drained into a deep network made up of sinusoidal capillaries in loops or whirls, situated in the upper part of the organ, whereas in the lower part a vast plexus is to be found. The blood from the deep network then flows into veins which also drain other hypothalamic regions and then flow into the anterior cerebral veinous system.The appearance of the vessels of the supra-optic crest and their special arrangement seems to indicate that they play a part in the as yet unknown function of the vascular organ of the supra-optic crest.

     

Structures de la cabuamine et de la vincorine

Cabuamine is identified as O-methyl-hydrogeno akuammine.     

Cancer de la prostate : utilité de la TEP-TDM à la F-fluorocholine

In oncology, positron emission computed tomography (PET/CT) has become an essential tool for initial staging, response evaluation and follow-up of cancer patients. Most of the frequent tumors (lung, breast, esophagus, and lymphomas) are highly avid for ¹⁸F-fluorodeoxyglucose (¹⁸FDG), but prostate cancer has not demonstrated significant uptake of FDG. The development of new tracers labeled with ¹⁸F such as choline analogs allowed already to obtain interesting results particularly in patients with biological relapse and inconclusive conventional imaging work-up. The impact of ¹⁸F-flurocholine PET/CT on patient management needs to be validated in large studies, but many centers use already this examination in order to guide further management, including radiotherapy planning.